before I indulge you, i bid you explain to me exactly what 1940's means Mr. Stark is using to track down the cube "energy" (then explain vita rays, that's always peaked my interest but not enough for a google search you see)

like I said before, they knew the origin point, the speed, the destination the duration, and the time of impact. Cap was intact apparently so I assume his two way was working(unless he wasn't wearing one) they could track that. Someone said the ship was off course, yea cap shifted it 45 degress south. Tracking radio signals is great deal easier than unknown cube energy(even in the faux 1940s).

It does help if the radios are transmitting I'll give you that.

How did they know the speed of the bomber? All they knew was where point of origin was and the destination. We don't know how long it took the ship at sea to even get remotely close to the area. By that time what was remaining of the bomber could've already moved about as the ice and landscape shifted. Radio frequency ended upon crashing to so it wouldn't have remained as that movement occurred.

Stark was able to trace the energy source of the cube IMO because of how strong the energy signal is from the thing and they already had measured that radiation (I'm sure) when they tested it in the lab. You're insinuating that because of Stark's tech saavy, he'd be able to find anything. He clearly has limitations as indicated by the scene with the car and the one with the submarine.

What's next? We gonna sit there and wonder why Cap didn't try to jump off the plane before impact? I mean it's pointless.